| 摘要 |
A microfiche reader is disclosed herein and includes an optical arrangement for providing an image of a supported microfiche on a projection screen. This optical arrangement utilizes a beam of light which is directed from a light source along a path through the microfiche and towards the back side of the screen. A condenser lens is located on this beam path between the microfiche and light source and includes a focal point also located on the path but on the other side of the microfiche. A projection lens assembly is located between the microfiche and the focal point of the condenser lens, again on the beam path, such that there is a predetermined spacing between the projection lens assembly and focal point. This spacing is selected to increase and preferrably maximize illumination efficiency of the overall optical arrangement.
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